Releasing mechanism for time fuses



Fe. 15, 1949. R. H. WHlTEHE AD I 2,461,793

RELEASING MECHANISM FOR TIME FUSES Filed July 11, 1939 INVENTOR AJczmpAAWv/zwiw ATTORNEY Patented Feb. 15, 1949 UNITE- Richard H. Whitehead,New Haven, Conn., as-

signor, by mesne assignments, to the United States of AmericaApplication July. 11, 1939,,Serial No. 283,725

3 Claims.

This invention relates to a releasing mechanism for time fuses.

These fuses generally comprisea timing mechanism anda firing pin soconnected that the firing pin wfll be discharged a predetermined lengthof time after the projectile leaves the gun. To determine thepredetermined length of'time there is contained within the fuse asettable member commonlyin the form of a disc connected to some externalportion of the fuse, for example the nose ofthefuse, in such a mannerthat the mechanical rotation ofithe nose of the fuse will rotate thedisc for setting purposes and the timing element is so designed thatonce the time train has started in motion it will rotate the disc for apredetermined amount,depending upon the setting, before releasing thefiring pin. The mechanism, therefore, involves two elements, namely therotatable cap or nose and the rotatable disc and during thesettingoperationthe nose and disc are in cooperativerelation. During thefiring operation it desirable that the nose and disc shall be.disconnected so that the tim train will not have to drag the nose withit as. it moves the disc Thi has heretoforeinvolved some connectionbetween the nose and the disc which will remain in engagement up to andincluding the time when the projectile is fired from the gun and whichwill be released at the time the projectile is fired to permit the timetrain itself to take up the movement' of the disc without moving thenose.

Acommon form of such connection has comprised a lug bent upwa dly fromthe disc in position to engage a pin upon the nose and a hammermechanismarranged to pound the lug down out of engagement with the pinas soon as the shell is subjected to the violent forces resultant fromthe firing of the propulsive charge. Little is known, however, of whatactually goes on inside the barrel of the gun during the minute.fraction of a second, while. the propulsive charge is being burned.Practical experience, however, leads'to theconclusion that this factoris variable, at least in some respect, since the hammer blow deliveredto; the lugis; sometimes suifioient to ,bend it out of the way of'thecontrolling pin and sometimes. it is'insufiicient, notwithstandingthe fact that the projectiles appearto be aqually influenced by thecharge.

It is an object of this invention to provide a newand improved mechanismfor insuring the disconnection between the rotatable noseand the timingdisc to permit the starting of the time train at. the time theprojectile leaves the; gun and i objects of the invention, referenceshould be had to the following detailed description, taken in connectionwith the accompanying drawing, in which:

Fig. 1 is a side elevation partly in section of T a time fuse embodyingthis invention, the section being taken along the line ll of Fig". 2."

Fig. 2 is a similar view being partially sectioned on the line 2 -2 ofFig. 1. i

Fig. 3 is a section on the line 3--3 of Fig. 1 with the unseen fork forthe latching pin superimposed upon the view in dotted lines toshow itscontour audits relationship to the pin.

Fig. l is a side elevation partly in section of a modfication of thedevice.

Fig. 5 is a bottom plan view of the construction of Fig. 4, with a fusemechanism removed.

Figs. 6' and 7 are fragmentary sectional views showing modifications ofthe device.

In the drawings the numeral 9 designates a conical portion of the fusehaving a rotable conical element iflmounted thereon terminating in apointed top H. The rotatable element H! has a recess l2 within-whichthere is fitted a time" fuse it, The general construction of the timefuse is irrelevant to this invention save that it contains some form ofa timing mechanism adapted to release a firing pin Hi afterpredetermined movement of the timing mechanism and that the length ofthis predetermined time is determined by the setting of a discillrotatable about the axis of the fuse. The disc 55 has an upstandingfork [5 having a slot' H and the body rotatable element l0 has a pin 13extending-downwardly withinthe slot H.

' The fuse I 3 is held rigidly upon the body 9 and the pin l8 and slotsH are so arranged that on rotation of the rotatable element lllthe discl5 is turned relative to the fuse to alter the setting thereof. Therotatable element ii] and the base 9 will be provided with correspondinggraduatlons 20 -2! so that the setting of the fuse maybe.

readily determined.

The means provided within the rotatable element NJ for freeing the sloti! from the pin It m rise a spr ng e men h ld" b scr ws .23

7 this character.

on the underside of a face 24 of the rotatable element I and carrying atthe diametrically opposite side a pair of weight 25 of such weight andso disposed that when the fuse is subjected to th jar of the propulsivecharge the weights 25 will bear down against the lug I6 and bendthe samedownwardly out of the path of the pin I8.

This is the common construction of fuses of Experience, however, hasshown that on some occasions the lug I6 is bent downwardlysatisfactorily and the fuse detonates after the predetermined lapse oftime. In other cases, however, the hammer blow of the weights 25 isinsuiiicient to accomplish this purpose.

1 It is an object of this invention to provide a mechanism which willinsure that the lug I6 shall be completely depressed and held out of thepath of the pin I1.

In the form of the invention embodied in Figures 1, 2 and 3 themechanism is provided for doing this, operable by the rotational inertiaand acceleration forces to which the projectile is subjected and inFigures 4 and 5 there is illustrated an alternative constructionoperable by the centrifugal factors.

Referring now to Figs. 1, 2 and 3, as will be seen, particularly fromFigure 2, there is out within the under face 24 of the rotat ble memberID a recess 26 adapted to receive a ball 21. This recess is disposedcircumferentially and has its upper surface inclined downwardly towardone point as shown at 28.

These projectiles are brought to a tremendous rotational speed duringthe slight fraction of a second while the projectile is within the boreof the gun and may attain speeds in the neighborhood of 12,000 to 24,000revolutions per minute within a period which may be less than .01 of asecond. This results in a very great rotational accelerating force andthe construction and arrangement of the ball 21 and of the recess 26 aresuch that during this excessive rotational acceleration the ball 21 ismoved circumferentially within the recess 26, passing, in its progress,the point 28 at that point depressing the spring element 22 downwardlyto press the lug I6 out of contract with the pin I'I far enough tocompletely free the pin.

The ball 21 will normally be at that end of the recess 26 in thedirection of rotation of the shell so that as the shell is rotated ittends to leave the ball behind and thereby moves it along the pathway.

In the form of the invention disclosed in Figs. 4 and 5 a recess 30 isprovided within the under 'face 24 extending in a radial direction andhaving an upper inclined surface and within that recess is provided aball 3I, the parts being so constructed and arranged that the ball isnormally held within its inner position as shown in Fig. 4, but when theprojectile is subjected to the very great centrifugal forces which areoperative when it attains its normal speed the ball is thrown outwardlyinsuring the depression of the spring 22 sufficient to bend down the lugto free the pin. Normally two such recesses 30 may be provided as shownin Fig. 5 and two such balls 3|. One such recess and ball being on eachside of the setting pin I1.

With either of the foregoing construction it will be clear that themotion of the shell within the gun will positively force down the lugfar enough so that even when the lug bends part way back due to its ownspring action it willnot come back far enough to re-engage the pin.

The form of the invention disclosed in Fig. 6 is so designed that thecap and setting disc are held in engagement by a ball which is releasedby centrifugal force. In this view there is provided in the rotatablemember ID a radially disposed groove 40 adapted to receive a ball Al.The spring finger I22 has a pin H8 adapted to engage the lug II'I uponthe disc II6. These parts in general being similar to the parts 22, I6,I1 and I8, except that the spring finger I22 is normally biased tospring away from the lug II! to free the parts from engagement but thisspring I22 has a slight depression 43 adapted to be engaged by the ball4| to hold the spring with the pin in engagement with the lug.

With this construction it will be clear that so long as the ball is inthe position shown in the drawing, the spring I22 will connect therotatable nose with the setting disc to permit the instrument to be setbut as soon as the shell is subjected to the rotative forces the ball IIis thrown outwardly permitting the spring finger I22 to disengage thelug.

In both of'these structures of Figures 1 to 5 it will be seen that thespring element 22 is illusv trated as carrying weights 25 for thepurpose of bending the lug I6 downwardly due to the set back of the fuseat the time of firing and when such lugs are used it will be clear thatthe force of the weights 25 acting as a hammer cooperate with the balls21 or 3| to force the lug I6 downwardly. Where such a construction isused an added factor of safety is provided in insuring that the elementswill be disconnected.

It will be noted, moreover, that whereas I have shown the ballinfluenced by the inertia under acceleration as in Figures 1, 2 and 3and by centrifugal, as shown in Figures 4 and 5, nevertheless byinclining the slot rearwardly as well as outwardly these two factors mayboth be brought to bear. I

It will be understood that whereas the set back occurs principally atthe time of firing and the rotational forces come into play only afterthe shell has started to move, nevertheless the lengths of time embodiedare so small that these forces may in practical effect operate together.

The form of the invention shown in Fig. 7 is similar to that shown inFig. 6 except that the groove I 40 instead of being radially disposed iscircumferentially disposed and the ball MI is so arranged that at oneposition within the groove it will hold the spring finger I22 inengagement with the lug II! but the groove will extend circumferentiallyaway from this position contrary to the direction of rotation of theshell so that as the shell is brought into rotation the acceleratingforce coupled with the inertia of the ball will move the ballcircumferentially to free the lug as previously described.

I have described this invention specifically as employing a ball as theelement to be released by the rotational forces but it will beunderstood that this is for convenience of illusstration and any type ofelement mounted to be released by these rotational forces could comewithin the broad scope of the invention and the word ball as used hereinis intended to be a generic term applicable to elements actuated by anysuch forces.

With any of these modifications it will be clear that the rotatable nosewill be held in setting engagement with the disc at all times until itis started in motion by reason of the fact that the ball prevents themovement of the spring pin. As soon, however, as the motion starts theball is thrown out of the way either by centrifugal action or byrotational acceleration.

With either of these modifications it will be seen that the ball in itsinitial or setting position is carried in a pocket to resistdisplacement but that-the set back forces at the time the shell is firedrelieve the ball from engagement with the nose because of the balls owninertia and hence leave the ball free to fly out of the pocket due.}tothe rotational forces.

Since certain changes may be made in the above cons'truction anddifferent embodiments of thew-invention could be made without departingfromthefscope thereof, it is intended that all matteiwontained in theabove description or shown in the accompanying drawing shall beinterpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent 15:

1; In a time fuse comprising a time train within a rotatable nose, a pinextending downwardly from said nose, a timing disc, and a lug extendingupwardly from said timing disc and having fingers defining a slot intowhich said pin extends to lock together said rotatable nose and saidtiming disc, a releasing mechanism comprising in combination asubstantially flat spring element spaced apart from said timing disc,one end of said spring element being secured to said nose, weightsattached to the other end of said spring element adjacent to saidfingers, a recess in said nose having a downwardly inclined uppersurface, and a ball in said recess adapted to be moved in the recess inresponse to rotational forces to depress said spring element and tothereby disengage said pin from said. fingers,

2. The device of claim 1 wherein the recess is circumferential, and theball is moved in the recess by inertia.

3. The device of claim 1 wherein the recess is radial, and the ball ismoved in the recess by centrifugal force.

RICHARD H. WHITEHEAD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 913,343 Wratzke Feb. 23, 19091,299,308 Doe Apr. 1, 1919 1,693,516 Junghans Nov. 2'7, 1928 FOREIGNPATENTS Number Country Date 480,145 Germany July 2'7, 1929

